Most keyboard instruments, including those used professionally and those used in the home, are not set up permanently. Therefore, a folding load support stand is necessary so that the keyboard and stand can be put away when not in use, and transported to other locations. A number of prior art devices use a scissoring pivoting legs to provide a folding stand. Each end of the scissoring legs has cross legs on it. The lower cross legs form feet and are used to provide stability, and the upper cross legs are used as load members to support the underside of the keyboard or other load. Since keyboards may be utilized in both sitting and standing modes, the angle of scissoring is varied to vary the height of the keyboard above the floor.
Some prior scissoring keyboard stands have an interconnection cross-member near the top of the stand. The cross-member may be in the form of a solid bar with a series of perforations so that when the stand is scissored for maximum height, such as when the user is standing, the bar protrudes beyond these scissoring members and sometimes even beyond the end of the keyboard. This produces an unattractive stand and one liable to upset if a person brushes against the cross-member (especially if this takes place before the keyboard is in position). Another approach is to use a flexible member such as a chain to connect between the two parts. Such stands are insubstantial in appearance and very unstable, especially when there is no weight on the stand, or when an upsetting force is placed on the keyboard (as by somebody brushing against the keyboard).
Therefore, for reasons of stability and appearance, it is desirable to lock the scissoring legs at their pivot point into a selected angular relationship,
One prior art device utilizes a disc welded or otherwise attached to one of the scissoring legs at the pivot point and a spring pin which protrudes through the other of the legs. A plurality of openings in the disc produce a limited number of adjustment positions. However, the spring pin components are very expensive to manufacture, and the limited selection of adjustment positions doesn't accommodate individual height preferences. In addition, welding is expensive to apply to high production rate products.
Accordingly, it is desirable to have a scissoring keyboard stand which locks into a substantial number of angular relationships between the pivoting legs, and which does not require expensive spring pins, castings, welding or machined parts, and yet presents a finished and durable appearance.